ALPHARETTA, Georgia (CNN) -- Latin music pulses from the stereo as 40 women jump, shimmy and sway to the beat.

Zumba is the most popular exercise class at one suburban Atlanta YMCA.

It's not a dance club. This is a regular morning exercise class at the YMCA in Alpharetta, Georgia. It's called Zumba.

Part dance, part aerobics, Zumba is an hourlong routine that works almost every muscle in the body.

"It is dance fitness," explained Stephanie Maxim, one of two class instructors. "We teach them moves that you can see on 'Dancing with the Stars': salsa, mambo, cha-cha, and we put it into a group fitness format."

"It's not like a workout," explained Diane Walterstiel, 55, of Alpharetta. "Before I come, I'm tense, but when I leave, I could kiss the world."

Nearly a year after being introduced at the YMCA in suburban Atlanta, Zumba is the most popular exercise offering at the facility.

"We turned exercise into a party," Perlman declared. "Zumba broke some of the rules of fitness. We used music in the original form instead of using step counts."

Perlman, whose background is in marketing, teamed up with Colombian dancer and choreographer Alberto "Beto" Perez in Miami in 2001.

"One day, Beto forgot his aerobics tapes, so he played his salsa and meringue songs during class in their original form," Perlman said. "People went crazy. They didn't feel like they were in a class with a drill sergeant."

Perlman said Perez decided to call the exercise Zumba, after the Colombian slang word meaning to buzz like a bee or move fast.

Zumba is now a brand name. Since 2003, Perlman's group has trained 20,000 instructors around the world and sold more than 3 million DVDs on the Internet and through infomercials, he said.